Abstract: Resistance elements having plural sheet resistances or resistance elements having different conduction types are formed on a semiconductor integrated circuit device in fewer steps. An oxide film is formed on a silicon semiconductor substrate. A poly-silicon film is formed on the silicon oxide film. A resist film is used to make poly-silicon pattern pieces 6a having an appropriate length in parallel. The widths of the pattern pieces are different. When boron is ion-implanted in two directions inclined to the substrate (at angles of 45° to the substrate surface from the upper left and the upper right), ion implanted areas are formed in both side faces of the pattern pieces. The resultant is annealed and then the impurity is diffused to be activated. This causes the formation of resistance elements having the different concentrations of the impurity, corresponding to the widths of the pattern pieces.